Method of introducing getter materials into incandescent lamps



Dec. 15 1925- D. M RAE METHOD OF INTRODUCINGQETTER MATERIALS INTO INCANDESCENT LAMPS Filed July 2 1921 HHHHI I IJ TI IHHI IU 1 66? p/wp a/eoru s INVENTOR Dwvcfl/v N/IcEfiE ATTORNEY Patented Dec. I5, 1925.

umrao srAras PATENT oran es.

DUNCAN MAORAE, OF EAST ORANGE, -NEW JERSEY, 'ASSIGNOB TO WESTINGHOUSE LAMP COMPANY, A CORPORATION OF PENNSYLVANIA.

- METHOD OF INTRODUCING GETIEB MATERIALS INTO INOANDESCENT IAMPS.

Application med July as, 1921. Serial mi. 488,098.

To all whom it may concern: e

Be it known that I, DUNCAN MACRAE, a citizen of the United States, and a resident of East Orange, in the county of Essex and State of New Jersey, have invented a new and useful Improvement in Methods of Introducing Getter Materials Into. Incandescent Lamps, of which the following is'a specification.

This invention relates to the manufacture of incandescent electric lamps and more particularly to the feature of introducing gases and vapors into the envelopes of the lamps.

An object of this invention is the provision of a novel method for introducing one or more materials into an envelope of an incandescent lamp.

Another object of the invention is to pro- .vide a method for mixing gases and vapors most satisfactory result is obtained.

Other objects of the invention will be ap parent from a reading of the following description.

It has been the practice in the manufacture of incandescent electriclamps tointro nation duce into the envelopes thereof. materials which assist in increasing the efliciencies of the lamps. As, for instance, mixtures of materials known in the art as getters have been placed in lamps and vaporized whereby they serve to eliminate certain detrimental eifects of residual gases and filament particles. Another. instance is the introduction of inert gases, such as argon'or nitrogen, which function beneficially throughout the lives of the lamps. ,Tliepresent practice of introducing the getter materials into lamps is to combine on the filaments. It has been the aim of the manufacturers to eliminate theuse of. these binders. While binders are not required for using in gas-filled lamps, it is found that there is no satisfactory manner of introducrials into lamps without the use of binders have been developed. One of these methods is set forth in my (so-pending application for improvements in getters and method of applying the same, filed May 19, 1921, Serial No. 470;672, whereinfis described a method of fusing certain materials to filament wires. Th s method, although satisfactory for the introduction of some materials, does not pro vide means for introducing all of the materials desired. The other method consists in coating a top tube or exhaust tube with phosphorus and. heating the coated portion durmg the exhaust operations. This method has not proved successful and it is further undesirable because it requires two separate and additional operations as well as an extra handling of each envelope.

The present invention contemplates a method for successfully and easily introduc ing predetermined amounts of materials into lampenvelopes :whereby the difliculties above outlined are overcome. In addition,

my method is particularly adapted for.in- V troducing phosphorus into the various types of lamps to render harmless any water vapor which may be present. The application of this method and. of the method set forth in my co-pending application, admits of the introduction of desired materials without the use of binders to materially increase the efliciencies of the lamps.

My method for economically and easily introducing desired materials into the lamp envelopes may be stated in one manner as consisting in regulating, over Wide ranges,

'them'with certain binders and mount them ing getter materials in vapor form in combiwith the gas. Up to the present time, two known methods of introducing matethe vapor pressure of the desired material in order to evolve definite quantities of vapor, and ,to conduct the vapor to lamp envelopes. It is known that the pressure of the vapor of a material may be governed or.

regulated by varying the composition, temperature, or pressure of a solid or liquid material in contact with and capable of exfolving the desired vapor. In regulating tlie pressure of the vapor by varying the composition, a non-volatile substance is preferably employed, in. order to avoid the introduction into the lamp of the vapor of such substance. I take advantage of this phenomenon and regulate the pressure 0 the vapor of 'a particular material to be in troduced-into' the lamp envelope to thereby regulate the uantity of the material to be *conducted tot e lamp. In any particular inin a container above the material in its solid or liquid form and create a pressure which will prevent the evolving of any further amount of the vapor. When this pressure is reduced, as by removing certain quantities of the vapor, the material will give' off vapor until the pressure of the vapor above the material'prevents the evolving of further vapors and thus restores equilibrium.

The application of my method for introducing a desired material into the lamp envelopes without the use of binders will be described in detail in connection with the introduction of phosphorus into both vacuum-type lamps and gas-filled lamps.

In the accompanying drawing, the single figure is adiagrammatic, illustration of a portion of an automatic exhaust machine and a container connected thereto for carrying the material to be vaporized.

-Referring now to the drawing, an envelope 1 of a vacuum lampis innormal'position in one of the holders 2 of an automatic exhaust machine and is connected, by a conduit 3, to an exhaust pump {L- The material to be introduced, in vapor form, into the envelope is placed in a suitable container 5 which is connected to conduit 3 by a short conduit 6- having therein a stop cock 7. In introducing phosphorus, I find that the desired white phosphorus may be economically obtained in its more active form by vaporizing the commercial form of red phosphorus and by regulating the temperature of its condensate or white phosphorus to obtain the desired pressure of the vapor. To this end, I providea separate container 8 connected to container 5 by conduit 9 which is also provided with a stop cook 10. After the red phos phorus has been introduced into container 8 and the latter has been evacuated, I heat the phosphorus and allow the vapor to pass into I container 5 where it is condensed. After a -phosphorus to evolve the desired quantities of vapor, I provide a suitable bath 11 of oil or other material which may be-heated or cooled in any desired manner to give a substantially uniform temperature to the phosphorus and the vapor evolved therefrom. After the predetermined quantity of white phosphorus has been vaporized, stop cock 7 is opened and thevapor admitted to the en 'velope 1 which has been exhausted by the normal operation of the automatic exhaust machine. The phosphorus operates in the lamp envelope, in the usual manner, to promote a first-class vacuum. The passing of a definite quantity of phosphorus vapor from from the condensate or phosphorus at the temperature of the bath.

The time required for the vapor pressure to equalize'within the bulb and within the container may be predetermined for a definitc vapor pressure and size of the communicating passage, and the pressure thereafter produced in the bulbs may be controlled by maintaining said communicating passage open for a predetermined time.

The application of my method for i'ntro ducing materials into gas-filled lamps is particularly advantageous as it permits vaporized phosphorus to be introduced and permits of a definite control of the quantities and operations of otherfmaterials. My method also provides a flexibility of operation in order that vapors of desired materials may be introduced into the lamp envelfope before the gas, or thatjthe vapors may be mixed with the gas and the mixture conducted into the lamp. In the first instance, when itis desired to introduce the vapor'first at a lower pressure than that at which it is \desired to introduce a gas, sucli as argon or nitrogen, I .find it desirable to exhaust the lamp in the usual manner,-'c1os'e' a stop cock 12"in conduit 13 for conducting gas from a suitable source (not shown) and open the stop cock 7 to permit the vapor to pass to the interior of the lamp. After the desired amount of vapor has. been introduced, the stop cock 7 is closed'and stop cock 12 is opened, thus permitting the gas, under desired pressure, to flow into the lamp. It is to be noted that stop cock 14 leading to the exhaust pump 4 will alsqbe closed during these operations. I

In thesecond instance, when 'it is desired to mix the gas with the vapor, I provide a conduit 15 leading from a suitable gas supply for the admission of the gas to container 5. The conduit 15 is provided with a stop cock' 16 for closing ofi the supply of gas when desired. After thegasxadmitted to the container has become saturated with the vapor at the temperature of the bath the stop cock 7 ,is opened and the combined vapor and gas allowed'to flow into the lamp envelope.

When the combined vapor andgas are introduced into, lamps by means of a flush exhaust machine, it is found that a certain portion of the vapor will adhere to the said material to a to equalize.

walls and to the mount of the lamp. The

quantity of the vapor retained in the envelope may be regulated so that suflicient material will be present to render the water vapor or other deleterious'materials harmless.

Although the foregoing description par; ticularly applies to the introduction ofother containers wherein they operate in a beneficial manner'to increase the life of incandescent lamps and to increase the operating efiiciencies thereof.

What is claimed is z y 1. The method of introducing a predetermined quantity of a vaporizable material into an envelope which consists in accu-' rately regulating the temperature of said vaporizable material to create a predetermined vapor pressure thereof in an enclosed container, exhausting said envelope and conducting said vapor from said container into said envelope.

2. The method of introducing a predetermined quantity of a vaporizable material into an envelope which consistsin heating (predetermined temperature to create a efinite vapor pressure thereof within a containing vessel, exhausting said envelope and con ucting the vapor from said vessel into said envelope.

3. The method of introducing a predetermined quantity of a vaporizable substance into an evacuated envelope which consists in heating said substance in an enclosed container'to a predetermined temperature to createa definite vapor pressure thereof and allowing the vapor pressure in the container and in the exhausted envelope 4. The method of introducing a predetermined'quantity of a vaporlzable substance into an evacuated envelope which consists in accurately regulating the t phosphorus into an evacuated envelope which consists in accurately controlling the temperature of -said. phosphorus in an enclosing vessel to create a predetermined vapor pressure thereof and allowing the vapor pressure in said vessel and in said evacuated envelope to equalize.

6. The method of introducing an inert gas and an active vapor into an evacuated envelope which consists in heating to a predetermined temperature, in a-- container, a substancecapable of evolving a vapor of the desired material, to create'a definite vapor ressure thereof, conducting an inert gas mto said container in contact with said vapor and then conducting the combined gas and vapor to the interior of said envelope.

7. The method of adding definite amounts of a vapor to an inert as to be introduced into a lamp envelo e w ich'consists in, disposing a body capa le of evolving vapor at definite partlal pressures in contact with an inert gas, heating said body to a predetermined temperature to evolve adefinite amount of vapor and conducting said gas and vapor into said lamp.

8. The method of addin a definite amount of a vapor to a quantity 0 argon or nitrogen gas to be introduced into an incandescent lamp which consists in heating a body capable of evolving a desired vapor to a predetermined temperature to obtain a prede-- termined vapor ressure thereof, conducting the vapor evolvedtherefrom into a supply of said argon or nitrogen gas and passing the combined gas and vapor into the lamp envelope;

In testimony whereof, I have hereunto subscribed my name this 27th day of July DUNCAN mcRAE. 

